Corrugated diaphragm manufacture



July 11, 1961 J. A. BROPHY, JR

CORRUGATED DIAPHRAGM MANUFACTURE 2 Sheets-Sheet 1 Filed March 19, 1956 0 INVENTOR.

ATTORNEY July 11, 1961 J. A. BROPHY, JR

CORRUGATED DIAPHRAGM MANUFACTURE 2 Sheets-Sheet 2 Filed March 19, 1956' ATTORNEY United States Patent 2,991,509 CORRUGATED DIATHRAGMv MANUFACTURE Joseph A. Brophy, Jr., River Edge, N.J., assignor to United States Rubber Company, New York, N.Y., a corporation of New Jersey Filed Mar. 19, 1956, Ser'. No. 572,288 3"Claims. (Cl.18'-56) This invention relates to corrugated diaphragm manufacture and more particularly to an improved flexible, corrugated diaphragm for connecting two articulated members such as train members, and an improved method of making said diaphragm.

Diaphragms now in use are usually of the following types. The first type consists of sheets of fibrous material which are folded to form pleats or corrugations, the latter being sewn along their edges to prevent the sheets from flattening out. As a rule, this type of diaphragm is not pro-formed to the cross-sectional contour of the articulated train members, depends solely on the length of the material tocornpensate for expansion or contraction as the train rounds a curve, and is prone to sag between the members, which decreases its abrasion resistance. Moreover, being made entirely of fabric, such diaphragms have. low flame resistance.

The second type consists of sheets of elastic material such as rubber, which may or may not be corrugated and which are usually molded in a press. Like the first type, the conventional elastic diaphragm is initially expensive to manufacture andis usually not pro-formed to the cross-sectional contour of the train members. Moreover, most of these elastic diaphragrns depend solely upon the stretchability ofv the material to compensate for expansion and contraction as the train members move into and out of longitudinal alignment. As a consequence, the elastic material is continuously under stress during such movement, especially at points of attachment to the train members, thereby substantially reducing the service life of such diaphragms.

Accordingly, an object of the invention is to provide an improved method of making a diaphragm wherein a continuous sheet of elastic material, prior to being cured, is pre-forrned over a mandrel to the cross-sectional co-n tour of the articulated train members and folded between.

a plurality of spacer plates. positioned alternately over. and under the sheet to form a plurality of corrugations therein, which corrugations extend continuously transversely of the membersv throughout the extent of the diaphragm to permit relative movement between the members.

Another object of the invention is to provide an improved corrugated diaphragm which is connected to the articulated train members in partially extended condition so that the corrugations therein can simultaneously expand and contract as the members move relatively into and out of longitudinal alignment, as when the. train rounds a curve, without depending solely upon the length or stretchability of the elastic diaphragm material but rather upon its resiliency, thereby prolonging its service life.

Another object of the invention is toprovide an improved method of making such diaphragms, which method has the advantages of low cost fabricating equipment, ease of fabrication, and produces a diaphragm whose finished appearance closely approximates that of a more costly molded item.

Still another object of the invention is to provide a diaphragm which acts as a protective cover for passengers when passing from one train member to the other, which in connecting the members will present the trainas one continuous unit, which has improved resistance to tearing, flame, abrasion and weather, which is adapted to ice connect various types of train members and effectively seal the same against weather, smoke and dust, and which, While being flexible, substantially maintains its crosssectional contour when connected between the members, under all conditions of stress or compression.

Other objects and advantages of this invention will become apparent upon consideration of the following specification and claims when read in conjunction with the accompanying drawings wherein:

FIG. 1 is a partial perspective view illustrating adiaphragm embodying the invention and serving toconnect two articulated train members as they round a curve;

FIG. 2 is a partial sectional view taken on line 2-2 of FIG. 1;

FIG. 3 is a partial sectional view taken on line 33 of FIG. 1;

FIG. 4 is a partial sectional view taken on line 44 of FIG. 1;

FIG. 5 is an elevational sectional view of the apparatus or form used in one method of practicing the invention;

FIG. 6 is a sectional view taken on line 66 of FIG. 5, with portions of the apparatus or form being broken away, and

FIG. 7 is a perspective view partially in section, illustrating the apparatus or form used in. a modification of the aforesaid method of practicing the invention.

Referring to FIG. 1, the flexible, corrugated diaphragm 10 is shown connecting the two articulated train members 111, 12. As will be apparent, the diaphragm 10 is formed to coincide with the cross-sectional contour of the members 11, 12, which in this instance, is substantially U-shaped. Referring to FIG. 2, the diaphragm 10 is attached to members 11, 12 by means of plates 13 and screws 14, and as will be seen from both FIGS. 1 and 2, diaphragm 10 is folded into a plurality of corrugations 15 which extend continuously transversely of members 11, 12 throughout the extent of the diaphragm.

The diaphragm 10 is preferably formed as a continuous sheet of elastic material such as natural or synthetic rubber, or the like, which may be internally reinforced with one or more layers of fibrous material, such as rayon tire cord or the like. In any event, the diaphragm 10 is sufliciently strong enough to support its own weight when connected between members 11, 12', that is, to substantially maintain its (and the train members) crosssectional shape, whether in extended or contracted position.

Referring to FIG. 2 once again, it illustrates the condtion of thediaphragm 10 at its central portion as the train members 11, 12 round a curve. This condition is substantially the same as when the diaphragm 10 is installed, wherein it is partially extended so that it can simultaneously expand and contract as the train members 11, 12 move into and out of longitudinal alignment, as when the train rounds a curve. FIG. 3, which is a section taken adjacent the inside of the curve, illustrates how the diaphragm 10" contracts when the members 11, 12 are close together; On the other hand, FIG. 4', which is a section taken adjacent the outside of the curve, illus1- trates the expanded condition of the diaphragm 10, when the members 11, 12 are far apart.

As will be pointed out more in detail below, the diaphragm 10 is cured in the contracted condition shown in FIG. 3. Accordingly, when installed between the members 11,. 12, the diaphragm 10" is partially extended; as shown in FIG; 2, but when permitted to do so, will return to its original, contracted condition because of. the re.- siliency of theelastic material. As will be apparent: from FIG. 4, the length of the diaphragm 10 is sulficient to permit the members 11, 12 to roundv a curve Without stretching the elastic materialitself. I 7

Accordingly, unlike the prior art fibrous, pleated diaphragms, the diaphragm is not reliant solely upon the length of material used, but rather upon its resiliency. Likewise, in contrast to conventional, un-corrugated elastic diaphragms, the diaphragm 10 does not rely solely upon the stretchability of the elastic material but rather upon its resilency, and is so designed that it is not con tinuously subjected to tensile stresses; therefore it will have a much longer service life.

In practicing the invention, the diaphragm 10 in fiat sheet form is laid over a mandrel having substantially the cross-sectional contour of the articulated train members, and is then folded between a plurality of spacer plates positioned alternately over and under the sheet to form a plurality of corrugations therein.

Referring to FIGS. 5 and 6, one method embodying the invention will now be described. The apparatus or form provided, comprises a substantially U-shaped mandrel 16 having an internal flange 17. Attached to flange 17 by means of screws 18 is a substantially U-shaped backing plate 19 which extends transversely of the mandrel =16 and outwardly from the flanged end thereof. The uncured fiat sheet comprising diaphragm 10 is laid over mandrel 16, one end of the sheet being folded transversely outwardly of the mandrel '16 and positioned against the backing plate 19. A substantially -U-shaped spacer plate 20 is then positioned over the sheet transversely of the mandrel 16 and is moved toward the backing plate 19 against the outwardly folded end of the sheet. Another substantially U-shaped spacer plate 21, slightly smaller in diameter than plate 20, is positioned under the sheet transversely of the mandrel 16 and is moved towards the plate 20 to fold the sheet outwardly therebetween transversely of the mandrel. Another plate 20 is placed over the sheet transversely of the mandrel 16 and is moved towards plate 21 to fold the sheet inwardly therebetween transversely of the mandrel, to form the first two corrugations 15.

The steps of positioning and moving additional spacer plates 20, 21 are then continued until the desired number of corrugations 15 are formed in the sheet. At this point, the opposite end of the sheet is then folded outwardly transversely of the mandrel 16, and another substantially U-shaped backing plate 22 is positioned against this outwardly folded opposite end.

The corrugated sheet forming diaphragm 10, the backing plates 19, 22 and the spacer plates 20, 21 are then clamped together by a plurality of the conventional C- clamps 23 (only one of which is shown) to form an assembly. The screws 18 are then taken out and this assembly, including backing plate 19, is removed from the mandrel 16 and placed in a vulcanizer (not shown) to cure the diaphragm 10. After curing, the assembly is removed from the vulcanizer and disassembled, the completed diaphragm 10 having the desired cross-sectional contour of train members 11, 12 in FIG. 1 as well as being in contracted condition as shown in FIG. 3.

Referring now to FIG. 7, a modified method of practicing the invention will now be described. The apparatus or form used therein comprises a pair of concentrically spaced inner and outer mandrels 24 and 25 respectively, and a backing plate 26 extending transversely of these mandrels and outwardly from one end of the inner mandrel 24 to the adjacent end of the outer mandrel 25. As will be apparent, both the procedural steps and the form or apparatus employed in this modified method are quite similar to those described above with reference to FIGS. 5 and 6; the mandrels 24, 25 and backing plate 26 having the substantially U-shaped crosssectional contour of the articulated train members 11, 12. However, in the modified method, the backing plate 26 rests upon the ground with the mandrels 24, 25 extending substantially vertically upwardly therefrom, as opposed to the substantially horizontal mandrel 16 in FIGS. 5 and 6.

The steps of laying the sheet forming diaphragm 10 over the inner mandrel 24, folding the ends of the sheet outwardly transversely of and between mandrels 24 and 25, positioning and moving the spacer plates (not numbered) relatively towards each other and the backing plate 26 to form the corrugations 15 in the diaphragm '10, and positioning the other backing plate 27 are all substantially the same as described above in reference to FIGS. 5 and 6. However, the assembly operation is speeded up and made easier because the mandrels 24 and 25 both act as guides, permitting the spacer plates to fall readily into position.

When the formation of the assembly has been completed, the various components are clamped together by a plurality of conventional C-clamps 28 (only one of which is shown) corresponding to G-clamps 23. However, the extra step of removing the assembly from the form is eliminated, as both are simply inserted within the vulcanizer (not shown) where the diaphragm 10 is cured. After curing, the assembly is removed from the vulcanizer and dissasembled, the completed diaphragm 10 having the desired cross-sectional contour of train members 11, 12 and being in contracted condition, as noted above in reference to FIG. 5 and 6.

The modified method of FIG. 7 is preferred where smaller and shorter diaphragms are to be made, because it is easier; quicker; requires less manual labor, and the forms can be made of relatively light weight, inexpensive material, so that a relatively large number of forms can be used without slowing down production by reason of having the forms in the vulcanizer. The method described with reference to FIGS. 5 and 6 is preferred where relatively larger and longer diaphragms are to be made, as well as where the corrugations formed are relatively deep, becausethe diaphragm is more accessible for adjustments which may become necessary during formation, than in the modified method. Also, since the mandrel 16 is relatively large and long, it is preferred that the assembly be removed therefrom in order to conserve space in the vulcanizing apparatus and to eliminate any mandrel down time.

While certain embodiments of the invention have been described and illustrated herein, it is to be understood that various modifications may be made in the invention without departing from the scope thereof, as defined in the appended claims. For example, the diaphragm 10 has been referred to herein as having a substantially U- shaped cross-section corresponding to that of the train members 11, 12. Obviously, the diaphragm and the forms employed could readily be modified to a complete or partial curvilinear or polygonal form for connecting not only train members, but other articulated members such as pipes, conduits, etc. In addition, the opposite ends of the sheet forming the diaphragm 10 need not be folded outwardly transversely of the mandrel, as in FIG. 5, but could be folded inwardly thereof so that the plates 13 in FIG. 2 would not be visible from the exterior of the train. Likewise, the diaphragm 10 could readily be fastened to the articulated members 11, 12 in other ways and by various other means such as zippers, bolts, etc.; or a plurality of diaphragms could be used to connect each pair of articulated members, which diaphragms, in turn, could be fastened together by zippers or like attaching means.

' Having thus described my invention, what I claim and desire to protect by Letters Patent is:

' 1. A method of making a flexible, corrugated diaphragm for connecting two articulated members, comprising the steps of laying a unitary sheet of elastic material over a mandrel having the cross-sectional contour of said members, positioning a first spacer plate having said contour over said sheet transversely of said mandrel, folding said sheet outwardly of said mandrel along said first spacer plate, positioning a second spacer plate having said contour under said sheet transversely of said mandrel, moving said second plate toward said first plate and against the portion of said sheet folded outwardly therebetween, folding said sheet inwardly of said mandrel along said second spacer plate, positioning a third spacer plate having said contour over said sheet transversely of said mandrel, moving said third plate toward said second plate and against the portion of said sheet folded inwardly therebetween, folding said sheet outwardly of said mandrel along said third spacer plate, continuing the aforesaid positioning, moving and folding steps with additional spacer plates in the same alternating sequence until the desired number of corrugations are formed in said sheet, clamping said sheet and said plates together, curing said sheet to set the same in corrugated'form, and thereafter unclamping said sheet and plates and removing the latter from said corrugated sheet.

2. A method of making a flexible, corrugated diaphragm for connecting two articulated members, comprising the steps of providing a form comprising a mandrel and a backing plate extending transversely of said mandrel and outwardly from one end thereof, said mandrel and said backing plate having the cross-sectional contour of said members, laying a unitary sheet of elastic material over said mandrel, folding one end of said sheet transversely of said mandrel, positioning said one end of said sheet against said backing plate, positioning a first spacer plate having said contour over said sheet transversely of said mandrel and against the folded end of said sheet, folding said sheet outwardly of said mandrel along said first spacer plate, positioning a second spacer plate having said contour under said sheet transversely of said mandrel and against the portion of said sheet folded along said first spacer plate, folding said sheet inwardly of said mandrel along said second spacer plate, continuing in an alternating sequence the positioning of additional first spacer plates over said sheet and associated outward folding of said sheet along said additional first spacer plates and the positioning of additional second spacer plates under said sheet and associated inward folding of said sheet along said additional second spacer plates substantially up to the other end of said sheet, to thereby form a plurality of corrugations in said sheet, positioning another backing plate having said contour against said other end of said sheet as folded transversely of said mandrel, clamping said sheet, said backing plates and said spacer plates together, curing said sheet to set the same in corrugated form, and thereafter unclamping said sheet and plates and removing the latter from said corrugated sheet.

3. A method of making a flexible, corrugated diaphragm for connecting two articulated train members, comprising the steps of providing a form comprising a pair of concentrically spaced inner and outer mandrels and a backing plate extending transversely of said mandrels and outwardly from one end of said inner mandrel to the adjacent end of said outer mandrel, said mandrels and said backing plate having the cross-sectional contour of said members, laying a unitary sheet of elastic material over said inner mandrel and within said outer mandrel, folding one end of said sheet transversely of and between said mandrels, positioning said one end of said sheet against said backing plate, positioning a first spacer plate having said contour over said sheet transversely of and between said mandrels, folding said sheet outwardly of said inner mandrel along said first spacer plate, positioning a second spacer plate having said contour under said sheet transversely of and between said mandrels, moving said second spacer plate against the portion of said sheet folded along said first spacer plate, folding said sheet inwardly of said inner mandrel along said second spacer plate, continuing the aforesaid positioning, moving and folding steps with additional spacer plates alternately over and under said sheet substantially up to the other end of said sheet, to thereby form a plurality of corrugations in said sheet, folding said other end of said sheet transversely of and between said mandrels and along the last spacer plate, positioning another backing plate having said contour against said other end of said sheet transversely of and between said mandrels, clamping said sheet, said backing plates and said spacer plates together, curing said sheet within said form to set said sheet in corrugated condition, and thereafter un clamping said sheet and plates and removing the latter from said corrugated sheet subsequent to extraction thereof from said form.

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